Fig. 5.

Effects of cytokines on the release and expression of DAF on HT-29 cells. Cells were incubated for 24 h with various concentrations of each cytokine. After each culture supernatant was collected, cells were detached and incubated with phosphatidylinositol-specific phospholipase C (PIPLC). After the medium was collected, the remaining cells were solubilized. The amounts of DAF in the culture supernatant, DAF released into the medium by PIPLC and DAF in the lysate of the remaining cells were determined by ELISA. (a) DAF which had shed into the culture supernatant. (b) PIPLC-sensitive cell surface DAF. (c) DAF in the lysate of the remaining cells. Values are expressed as a percentage of that of the control in which cytokines were not present. Values shown are means of four experiments.